Faculdade de Ciências e Tecnologia
Universidade do Algarve 
E-mail: jlongras@ualg.pt
URL: http://w3.ualg.pt/~jlongras/  
     

Publications 
Patents
Thesis

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Publications:

• Conversion of Phase Modulated Signals from Optical Network to Wireless Domain using Resonant Tunneling Diode Optoelectronic Integrated Circuits, Horacio Cantu; Bruno Romeira; Krishna Seunarine; Anthony Kelly; Charles Ironside; Jose Figueiredo; presented at The Optical Fiber Communication Conference 2012 (OFC/NFOEC 2012). 
  
• A Self-Synchronized Optoelectronic Oscillator based on an RTD Photo-Detector and a Laser Diode, B. Romeira, K. Seunarine, C. N. Ironside, A. E. Kelly, J. M. L. Figueiredo, Photon. Technol. Lett., 23 (16), pp. 1148-1150, 2011.  JCR® impact factor: 1.987
• DC Characterization of Tunnel Diodes Under Stable Non-Oscillatory Circuit Conditions, L. Wang,  J. M. L. Figueiredo, C. N. Ironside, E. Wasige, IEEE Transactions on Electron Devices, 58 (2), pp. 343-347, 2011.  JCR® impact factor: 2.255
  
• Compact RF modulated laser diodes for atomic spectroscopy, K. Seunarine, B. Romeira, G., H. Cantu, M.J. Steer, G. Tandoi, C.N. Ironside, J.M.L. Figueiredo, D.J. Paul, A. Luiten., accepted in the International Quantum Electronics Conference / Conference on Lasers and Electro-Optics (IQEC/CLEO), Pacific Rim, Sydney 28 Aug-1 Sep 2011.
• Nonlinear dynamics of a Liénard delayed-feedback optoelectronic oscillator, B. Romeira, J. M. L. Figueiredo, C. N. Ironside, K. Seunarine, and J. Javaloyes, Joint conference Third International Workshop on Nonlinear Dynamics and Synchronization (INDS'11) and Sixteenth International Symposium on Theoretical Electrical Engineering (ISTET'11), Session: Nonlinear Dynamics, chaos and Synchronization - 2, Klagenfurt, Austria, July 25-27, 2011.
• Clock Recovery of an Injection-Locked Resonant Tunneling Diode Microwave-Photonics Oscillator, B. Romeira, L. M. Pessoa, H. M. Salgado, S. Silva, J. M. L. Figueiredo, 13th International Conference on Transparent Optical Networks (ICTON 11), paper We.C5.6, Stockholm, Sweden, June 26-30, 2011.  
  
• Optoelectronic Oscillator Topologies based on Resonant Tunneling Diode Fiber Optic Links, B. Romeira, J. M. L Figueiredo, K. Seunarine, C. N. Ironside, International Conference on Applications of Optics and Photonics (AOP11), Proc. SPIE 8001, 80011T, Braga, Portugal, May 3-7, 2011.
• A Liénard optoelectronic oscillator with time-delayed feedback, B. Romeira, K. Seunarine, C. N. Ironside, J. Javaloyes, A. E. Kelly, J. M. L. Figueiredo, The European Conference on Lasers and Electro-Optics (CLEO) and the European Quantum Electronics Conference (EQEC) Conference Digest, OSA Technical Digest (CD) (Optical Society of America, 2011), paper CI3.2, Munich, Germany, May 22-26, 2011.
  
• Review of optoelectronic oscillators based on modelocked lasers and resonant tunneling diode optoelectronics, C. N. Ironside, M. Haji, L. Hou, J. Akbar, A. E. Kelly, K. Seunarine, B. Romeira, J. M. L. Figueiredo, International Conference on Applications of Optics and Photonics (AOP11), Proc. SPIE 8001, 80011T, Braga, Portugal, May 3-7, 2011
• Optoelectronic Oscillators for Communication Systems, B. Romeira, J. M. L Figueiredo (2010).  Emerging Trends in Technological Innovation, Camarinha-Matos, Luis M.; Pereira, Pedro; Ribeiro, Luis (Eds.), IFIP International Federation for Information Processing, Vol. 314, ISBN: 978-3-642-11627-8, Springer.
  
• Resonant Tunnelling Optoelectronic Circuits, José Figueiredo, Bruno Romeira, Thomas Slight and Charles Ironside (2010). Advances in Optical and Photonic Devices, Ki Young Kim (Ed.), ISBN: 978-953-7619-76-3, InTech.
  
• Optoelectronic switching in semiconductor waveguides incorporating a resonant tunneling diode, J. M. L. Figueiredo, A. R. Boyd, C. R. Stanley, C. N. Ironside, and A. M. P. Leite. OSA Trends in Optics and Photonics, Vol. 32, Photonics in Switching, Paul R. Prucnal and Daniel J. Blumenthal, eds, Optical Society of America, Washington, DC 2000. (Reprinted from Photonics in Switching Conference, 1999 Tecnical Digest.)
  
• Optical Control of a Resonant Tunneling Diode Microwave-Photonic Oscillator, B. Romeira, J. M. L. Figueiredo, C. N. Ironside, A. E. Kelly, T. J. Slight, IEEE Photonics Technology Letters, vol. 22, no. 21, pp. 1610-1612, 2010.  JCR® impact factor: 1.987
• Chaotic Dynamics in Resonant Tunneling Optoelectronic Voltage Controlled Oscillators, B. Romeira, J. M. L. Figueiredo, C. N. Ironside, T. J. Slight, IEEE Photonics Technology Letters, vol. 21, no. 24, pp. 1819-1821, 2009.  JCR® impact factor: 1.987
• Nonlinear Dynamics of Resonant Tunneling Optoelectronic Circuits for Wireless/Optical Interfaces, B. Romeira, J. M. L. Figueiredo, T. J. Slight, L. Wang, E. Wasige, C. N. Ironside, A. E. Kelly, R. Green,IEEE Journal of Quantum Electronics, vol. 45, no. 11, pp. 1436-1445, 2009.  JCR® impact factor: 2.477
• Synchronization and Chaos in a Laser Diode Driven by a Resonant Tunneling Diode, Bruno Romeira, José M. L. Figueiredo, Thomas J. Slight, Liquan Wang, Edward Wasige, Charles N. Ironside, José M. Quintana, and Maria J. Avedillo, IET Optoelectronics 2 (6), 211-215 (2008).  JCR® impact factor: 1.105
• A Liénard Oscillator Resonant Tunnelling-Laser Diode Hybrid Integrated Circuit: Model and Experiment, T. J. Slight, B. Romeira, L. Wang, J. M. L. Figueiredo, E. Wasige, and C. N. Ironside, IEEE J. Quant. Electron. 44 (12), 1158-1163 (2008).  JCR® impact factor: 2.477
• Self-oscillation and period adding from a resonant tunnelling diode – laser diode circuit, J. M. L. Figueiredo, B. Romeira, T. J. Slight, L. Wang, E. Wasige, and C. N. Ironside, Electron. Lett. 44 (14), 876-877 (2008).  JCR® impact factor: 1.001
• Coherent approach to transport and noise in double-barrier resonant diodes, V.  Ya. Aleshkin, L. Reggiani, N. V. Alkeev, V. E. Lyubchenko, C. N. Ironside, J. M. L. Figueiredo, and C. R. Stanley, Phys. Rev. B, 70, 115321 (2004).  JCR® impact factor: 3.772
• Giant suppression of shot noise as signature of coherent transport in double barrier resonant diodes, V.Ya. Aleshkin, L. Reggiani, N.V. Alkeev, V.E. Lyubchenko, C.N. Ironside, J.M.L. Figueiredo, C.R. Stanley, Semicond. Sci. Technol., 19 4, S161-S163 (2004).  JCR® impact factor: 0.988
• Modeling of Light Sensitive Resonant-Tunneling-Diode Devices, I. J. S. Coêlho, J. F. Martins-Filho, J. M. L. Figueiredo, and C. N. Ironside, Journal of Applied Physics, 95, 12, pp. 8258-8263 (2004).  JCR® impact factor: 2.064
• Reply to Comment on "Giant suppression of shot-noise in double barrier resonant diode: a signature of coherent transport", V.Ya. Aleshkin, L. Reggiani, N.V. Alkeev, V.E. Lyubchenko, C.N. Ironside, J.M.L. Figueiredo, C.R.Stanley, Semicond. Sci. Technol. 19, 5, pp. 665-666 (2004).  JCR® impact factor: 1.323
• Giant suppression of shot noise in double barrier resonant diode: a signature of coherent transport, V.Ya. Aleshkin, L. Reggiani, N.V. Alkeev, V.E. Lyubchenko, C.N. Ironside, J.M.L. Figueiredo, C.R. Stanley, Semicond. Sci. Technol. 18, 6, L35-L38 (2003).  JCR® impact factor: 1.323
• Ultralow voltage resonant tunnelling diode electroabsorption modulator, J. M. L. Figueiredo, C. N. Ironside, and C. R. Stanley, Journal Modern Optics, 49, 5, pp. 939 - 945 (2002).  JCR® impact factor: 0.98
• Current noise in resonance tunnel diodes based on InGaAlAs heterostructures, V. Alkeev, V. E. Lyubchenko, C. N. Ironside, J. M. L. Figueiredo, C. R. Stanley, Journal of Communications Technology and Electronics, 47, 2, pp. 238-231 (2002).  JCR® impact factor: 0.339
• Current noise in resonance tunnel diodes based on InGaAlAs heterostructures, Alkeev, N. V.; Lyubchenko, V. E.; Ironside, C. N.; Figueiredo, J. M. L.; Stanley,C. R., Radiotekhnika i Elektronika, 47, 2, pp. 249-252 (2002).
• Electric field switching in a resonant tunneling diode electroabsorption modulator, J. M. L. Figueiredo, C. N.  Ironside, and C. R. Stanley, IEEE Journal of Quantum Electronics, 37, 12, pp. 1547-1552 (2001).  JCR® impact factor: 2.477
• Superhigh-Frequency Characteristics of Optical Modulators on the Basis of InGaAlAs Resonance-Tunnel Heterostructures,  N. V. Alkeev, V. E. Lyubchenko, C. N. Ironside, J. M. L. Figueiredo, and C. R. Stanley, Journal of Communications Technology and Electronics, Vol. 45, No. 8, pp. 911-914 (2000).  JCR® impact factor: 0.339
• Superhigh-frequency characteristics of optical modulators on the basis of InGaAlAs resonance-tunnel heterostructures, Alkeev,N. V.;Lyubchenko,V. E.;Ironside,C. N.;Figueiredo,J. M. L.;Stanley,C. R., Radiotekhnika i Elektronika, 45, 8, pp. 1010-1013 (2000).
• Resonant tunneling diode electro-absorption waveguide modulator operating at around 1550 nm, Figueiredo, J. M. L.; Leite,A. M. P.; Ironside,C. N.; Stanley,C. R.; McMeekin, S. G.; Bouris,K.;Moodie,D. G.; Pacific Rim Conference on Lasers and Electro-Optics, CLEO - Technical Digest, pp. 596-597         (2000) .  
• Optical modulation at around 1550 nm in a InGaAlAs optical waveguide containing a InGaAs/AlAs resonant tunneling diode,  J. M. L. Figueiredo, A. R. Boyd, C. R. Stanley, C. N. Ironside, S. G. McMeekin, and A. M. P. Leite, Applied Physics Letters, Vol. 75, No. 22, pp. 3443-3445 (1999).  JCR® impact factor: 3.820
• Optical modulation in a resonant tunneling relaxation oscillator, J. M. L. Figueiredo, C. R. Stanley, A. R. Boyd, C. N. Ironside, S. G. McMeekin, and A. M. P. Leite, Applied Physics Letters, Vol. 74, No. 9, pp. 1197-1199 (1999).   JCR® impact factor: 3.820
• Integration of a RTD with an optical waveguide to form a high speed electroabsorption modulator, Figueiredo, J. M. L.; Ironside,C. N.; Leite,A. M. P.; Stanley, C. R.; IEE Colloquium (Digest), 372, pp. 6/1-6/6 (1997).   
  
• Applications of laser diode sources with integrated resonant tunnelling diode technology, C. N. Ironside, B. Romeira, K. Seunarine, , A. E. Kelly, T. J Slight, and J. M. L. Figueiredo, Photonex2010 – Industry Programme, C6: Novel Sources and detectors, Telford, UK, 3-4 November 2010.
  
• Optoelectronic Oscillators for Communication Systems, B. Romeira and J. M. L Figueiredo, 1st IFIP Doctoral Conference on Computing, Electrical and Industrial Systems (DoCEIS’10), Costa de Caparica, Portugal, February 22-24, 2010. 
  
• An Optoelectronic Oscillator based on a Resonant Tunneling Diode Photo-Detector Integrated Chip, B. Romeira, K. Seunarine, C. N. Ironside, A. E. Kelly, T. J Slight, J. M. L. Figueiredo, The 23rd Annual Meeting of the IEEE Photonics Society, paper MD4, Denver, Colorado, USA, 7-11 November, 2010.  
  
• Microwave-Photonic Oscillators for Radio-over-Fibre Access Networks, J. M. L. Figueiredo, B. Romeira, T. J. Slight, C. N. Ironside, VIII Symposium On Enabling Optical Networks and Sensors (SEON 10), FEUP, Porto, Portugal, 2010. 
  
• Microwave Photonic Oscillators for Femtocellular Access Networks, B. Romeira, T. J. Slight, A. E. Kelly, C. N. Ironside, J. M L Figueiredo, 15th European Conference on Networks and Optical Communications (NOC 2010), Components and modulation strategies, Faro-Algarve, Portugal, 8-10 Junho 2010. 
  
• Optical injection locking of a resonant tunneling diode - optical waveguide photo-detector, Bruno Romeira, José Figueiredo, C. N. Ironside, A. E. Kelly, T. J. Slight, 15th European Conference on Integrated Optics (ECIO 2010), Cambridge, April 7-9, 2010. 
  
• Resonant tunneling diode opto-electronic integrated circuits (Invited Paper), Charles N. Ironside, José M. L. Figueiredo, Bruno Romeira, Thomas J. Slight, Liquan Wang, Edward Wasige, Photonics West 2010, Nanotechnologies in Photonics, 7608: Quantum Sensing and Nanophotonic Devices VII, Session 4:  Quantum Structures and Devices I, Paper 7608-16. 
  
• Wireless Injection Locking and Phase Noise Reduction in a Semiconductor Laser driven by a Resonant Tunnelling Diode Nonlinear Oscillator, B. Romeira, J. M. L Figueiredo, T. J. Slight, L. Wang, E. Wasige, and C. N. Ironside, The European Conference on Lasers and Electro-Optics (CLEOEUROPE 2009) (14 - 19 June, Munich, Germany), Session Title: Fixed and Wireless Access Networks, paper CI3.1.
  
• Wireless/Photonics Interfaces Based on Resonant Tunneling Diode Optoelectronic Oscillators, B. Romeira, J. M. L Figueiredo, T. J. Slight, L. Wang, E. Wasige, and C. N. Ironside, Conference on Lasers and Electro-Optics and Quantum Electronics and Laser Science (CLEO/QELS 2009) (May 31 – June 5, 2009, Baltimore, Maryland, USA), Session Title: Microwave Photonics, paper CTuT4. 
  
• Wireless-photonics-wireless interfaces based on resonant tunneling diode optoelectronic oscillators, J. M. L. Figueiredo, C. N. Ironside, B. Romeira, J. M. L Figueiredo, T. J. Slight, L. Wang, E. Wasige, European workshop on photonics solutions for wireless, access, and in-house networks (18-20 May 2009, Duisburg, Germany), Session Title: . (PDF PDF)
• Resonant tunneling diode-laser diode optoelectronic integrated circuit operating as a voltage controlled oscillator  (Invited Paper), C. N. Ironside, J. M. L. Figueiredo, B. Romeira, T. J. Slight, E. Wasige, L. Wang, Microtechnologies for the New Millennium - Conference: Photonic Materials, Devices, and Applications (4 - 6 May 2009, Maritim Hotel, Dresden Germany), Session 8B:  Photonic Devices, Paper 7366-39. 
  
• Wireless to Optical Frequency Locking and Chaos using a Resonant Tunnelling - Laser Diode Circuit, B. Romeira, J. M. L. Figueiredo, T. J. Slight, L. Wang, E. Wasige, and C. N. Ironside, 2009 IEEE/LEOS Winter Topical Meetings (WIN2009), Innsbruck, Austria, 12 -14 January 2009. 
  
• Synchronizing Optical to Wireless Signals Using a Resonant Tunneling Diode Laser Diode Circuit, B. Romeira, J. M. L. Figueiredo, T. J. Slight, L. Wang, E. Wasige, and C. N. Ironside, The 21st Annual Meeting of The IEEE Lasers and Electro-Optics Society (LEOS 2008) Newport Beach, California, 9-13 November 2008. 
  
• Optoelectronic Integration of a Resonant Tunneling Diode and a Laser Diode, B. Romeira, J. M. L. Figueiredo, T. J. Slight, L. Wang, E. Wasige and C. N. Ironside, 14th European Conference on Integrated Optics (ECIO 2008), Eindhoven, The Netherlands, June 11-13, 2008. 
• Observation of Frequency Division and Chaos Behavior in a Laser Diode driven by a Resonant Tunneling Diode, Bruno Romeira, José M. L. Figueiredo, Thomas J. Slight, Liquan Wang, Edward Wasige, Charles N. Ironside, José M. Quintana3, and Maria J. Avedillo3, Conference on Lasers and Electro-Optics and Quantum Electronics and Laser Science (CLEO/QELS 2008), San Jose, California, May 4-9 2008. 
  
• Synchronization and Chaos in a Laser Diode Driven by a Resonant Tunneling Diode, Bruno Romeira, José M. L. Figueiredo, Thomas J. Slight, Liquan Wang, Edward Wasige, Charles N. Ironside, José M. Quintana, and Maria J. Avedillo, Conference on Semiconductor and Integrated Optoelectronics (SIOE 2008), Cardiff, Wales, UK, 31 March - 2 April 2008. 
  
• Generation of optical chaotic signals, B. Romeira, J. M. L. Figueiredo, T. J. Slight, L. Wang, E. Wasige, C. N. Ironside, 16th Conferência Nacional de Física (FÍSICA 08), Lisboa, Portugal, 03-06 Setembro 2008. 
  
• Novel Optoelectronics Circuits Employing Resonant Tunnelling Diodes, B. Romeira, J. M. L. Figueiredo, T. J. Slight, L. Wang, E. Wasige, C. N. Ironside, J. M. Quintana, M. J. Avedillo,  2nd International Conference on Advanced Nano Materials (ANM 08) , Aveiro, Portugal, 22-25 Junho 2008.
• Chaotic Behavior in Optoelectronic Circuits Employing Resonant Tunneling Diodes, B. Romeira, J. M. L. Figueiredo, T. J. Slight, L. Wang, E. Wasige, C. N. Ironside, J. M. Quintana, M. J. Avedillo, 2nd Workshop on Low-Dimensional Structures: Properties and Applications (WLDS 08), Aveiro, Portugal, 31 Janeiro-01 Fevereiro 2008. 
  
• Optoelectronic integrated circuits incorporating negative differential resistance devices (invited), J. M. L. Figueiredo, B. Romeira, T. J. Slight, L. Wang, E. Wasige, and C. N. Ironside, V Symposium On Enabling Optical Networks and Sensors (SEON 2007), Aveiro, Portugal, 29 Junho 2007. 
  
• Optoelectronic characterization of structures based on tunnel junctions, tunnel barriers and quantum dots, J. M. L. Figueiredo, B. Romeira, A. Brázio, International School on Structural Characterization of Nanostructures (ISSCN 07) , Aveiro, Portugal, 25-27 Janeiro 2007. 
  
• Modelling of a Resonant Tunnelling Diode Optical Waveguide Modulator, J. J. N. Calado, J. M. L. Figueiredo, 21st International Conference on Amorphous and Nanocrystalline Semiconductors, ICANS 21, Lisboa, Setembro de 2005.
  
• Modeling of a Resonant Tunneling Diode Optical Modulator, J. J. N. Calado, J. M. L. Figueiredo, and C. N. Ironside, The 2005 International Microwave and Optoelectronics Conference (IMOC), Julho de 2005. 
  
• Development of an optical fiber imaging system for nanocrystal-biosensors, R. Baltazar, J. M. L. Figueiredo, G. N. M. Ferreira, EuroConference on Biomaterials, Biosensors and Analytical Techniques, 18-23 June 2005. 
  
• Modelling of a modulator based on resonant tunnelling diode switching, J. J. N. Calado, J. M. L. Figueiredo, and C. N. Ironside, 12th IEEE International Symposium on Electron Devices for Microwave and Optoelectronic Applications, 8 - 9 November (2004). 
  
• Experimental measurements of the ridge spacing influence on the frequency response and optical spectrum of laterally coupled laser diodes, Horacio Lamela, Rui Santos, Guillermo Carpintero, Jean-Pierre Vilcot, A. Barsella, J. Figueiredo, Markus Pessa, Proc. SPIE Vol. 4986, Physics and Simulation of Optoelectronic Devices XI; Marek Osinski, Hiroshi Amano, Peter Blood; Eds., pp. 86-91 (2003). 
  
• Optical modulators employing resonant tunneling diodes, C. N. Ironside, J. M. L. Figueiredo, and C. R. Stanley, 26th Workshop on Compound Semiconductor Devices and Integrated Circuits held in Europe, Conference Proceedings, May 21- 26 (2002). 
  
• The Electric Field Switching in Resonant Tunneling Diode Electroabsorption Modulator, J. M. L. Figueiredo, C. N. Ironside, and C. R. Stanley, Optical Fiber Communication Conference (OFC), Conference Proceedings Vol. 3, pp. wdd62-1 wdd62-3 (2001).
  
• Ultra-broad-band photodetection in a resonant tunneling device, Martins JF, de Araujo RE, Gomes ASL, Leite JRR, Figueiredo JML, Stanley CR, Ironside CN, SBMO - IEEE MTT-S International Microwave and Optoelectronics Conference, AUG 06-10, IMOC 2001, pp. 325-328. 
  
• Ultralow voltage resonant tunnelling diode electroabsorption modulator, J.M.L. Figueiredo, C.N. Ironside, C.R. Stanley, A. Meikle, 15th National Quantum Electronics and Photonics Conference (2001). 
  
• Visible to Mid-Infrared Photodetection in a Resonant Tunneling Device, J. F. Martins-Filho, R. E. de Araújo, A. S. L. Gomes, J. M. L. Figueiredo, C. R. Stanley, and C. N. Ironside, Conference on Lasers and Electro-Optics - Europe (CLEO/Europe) Focus Meetings 2001, Conference Proceedings (2001). 
  
• Resonant Tunneling Device as a Visible to Mid-Infrared Photodetector R. E. de Araujo, A. S. L. Gomes, J. R. Rios Leite, J. F. Martins-Filho, J. M. L. Figueiredo, C. R. Stanley, C. N. Ironside, XXIV encontro nacional de física da matéria condensada, São Lourenço - MG, 15 a 19 de Maio de 2001. 
  
• High Photodetection Gain in a Resonant Tunneling Diode Waveguide Modulator/Detector, J. F. Martins-Filho, R. E. de Araújo, A. S. L. Gomes, J. M. L. Figueiredo, C. R. Stanley, and C. N. Ironside, in Proceedings IEEE LEOS 2000, 13th Annual Meeting IEEE Lasers and Electro-Optics Society (LEOS-2000), Vol. 1, pp. 15 -16. 
  
• Electric field switching in a resonant tunneling diode electroabsorption modulator, J. M. L. Figueiredo, C. N. Ironside, and C. R. Stanley, 8th IEEE International Symposium on High Performance Electron Devices for Microwave and Optoelectronic Applications (EDMO 2000), University of Glasgow, 2000, Conference Proceedings, pp. 146 -151. 
  
• 40 dB Photodetection Gain in a Resonant Tunneling Diode Optical Waveguide, J. F. Martins-Filho, R. E. de Araujo, A. S. L. Gomes, J. M. L. Figueiredo, C. R. Stanley, and C. N. Ironside, IX Simpósio Brasileiro de Microondas e Optoeletrônica, João Pessoa - PB, Brazil, 7-10 August 2000, Conference Proceedings. 
  
• Resonant Tunneling diode electro-absorption waveguide modulator operating at around 1550 nm, J. M. L. Figueiredo, A. M. P. Leite, C. N. Ironside, C. R. Stanley, S. G. McMeekin, K. Bouris, and D. G. Moodie, Conference on Lasers and Electro-Optics (CLEO 2000), 2000, OSA Technical Digest Series, pp. 596-597. 
  
• Microwave properties of InGaAlAs resonant-tunneling optical modulators, V. E. Lyubchenko, N. V. Alkeev, C. N. Ironside, J. M. L. Figueiredo, C. R. Stanley, 13th International Conference on Microwaves, Radar and Wireless Communications (MIKON-2000), Conference Proceedings Vol. 1, pp. 140 -143, 2000. 
  
• Self-oscillation in a resonant tunnelling diode electroabsorption modulator, J. M. L. Figueiredo, C. N. Ironside, A. R. Boyd, C. R. Stanley, A. M. P. Leite, and S. G. McMeekin, Conference on Lasers and Electro-Optics (CLEO 1999), OSA Technical Digest Series, Optical Society of America, pp. 125-126.
  
• Optical modulation at around 1550nm in a InGaAlAs optical waveguide containing a InGaAs/AlAs resonant tunnelling diode, J. M. L. Figueiredo, A. M. P. Leite, C. N. Ironside, A. R. Boyd, C. R. Stanley, and S. G. McMeekin, Quantum Electronics & Photonics Conference (QE-14), 6-9 Sept. 1999, UK, Conference Proceedings, paper 16.2. 
  
• Optoelectronic switching in semiconductor waveguides incorporating a resonant tunneling diode, J. M. L. Figueiredo, A.R. Boyd, C.R. Stanley, C.N. Ironside, and A.M.P. Leite, Photonics in Switching Conference, 1999 Technical Digest, Optical Society of America, paper JWB3. 
  
• High speed optical waveguide modulator based on resonant tunnelling effect, J. M. L. Figueiredo, C. N. Ironside, C. R. Stanley, and A. M. P. Leite, Conference on Lasers and Electro-Optics - Europe (CLEO/Europe 1998), Conference Proceedings 1998 IEEE Catalog No. 98TH 8326, pp. 20-20. 
  
• High frequency optical modulation in a resonant tunneling transmission line oscillator, J. M. L. Figueiredo, C. N. Ironside, A.R. Boyd, C. R. Stanley, and A. M. P. Leite, 6th IEEE International Workshop on High Performance Electron Devices for Microwave and Optoelectronic Applications (EDMO'98), Conference Proceedings 1998 IEEE Catalog No. 98TH8345, pp. 240-245.
  
• Integration of a resonant tunneling diode and an optical waveguide to form an electroabsorption modulator with a large bandwidth to drive voltage ratio, J. M. L. Figueiredo, A. M. P. Leite, C. R. Stanley, and C. N. Ironside, Conference on Lasers and Electro-Optics 1998, Vol. 6, OSA Technical Digest Series, Optical Society of America, pp. 263-264.
  
• Modulação Óptica a Alta Frequência Usando o Efeito de Túnel Ressonante, J. M. L. Figueiredo, C. N. Ironside, e A. M. P. Leite, Conferencia Nacional de Física, 1998, Porto, Actas, pp. - .
• High-speed electroabsorption modulator by integration of a RTD with an optical waveguide, J. M. L. Figueiredo, C. N. Ironside, A. M. P. Leite, and C. R. Stanley, The Rank Prize Funds Mini-Symposium on Ultrafast Photonic Processing and Networks, 20th to 23rd April 1998.
  
• High Speed Electroabsorption Modulator by Integration of a RTD with an Optical Waveguide, J. M. L. Figueiredo, C. N. Ironside, A. M. P. Leite, and C. R. Stanley, Best student poster paper, 5th IEEE International Workshop on High Performance Electron Devices for Microwave and Optoelectronic Applications (EDMO'97), Conference Proceedings 1997 IEEE Catalog No. 97TH8305, pp. 352-357.  
  
• Design and Fabrication of Low Loss Passive Polymeric Waveguides Based on Mass Replication Technique, A. Neyer, T. Knoche, L. Muller, P. C. Lee, J. H. Kim, M. A. Andrade, J. Carvalho, J. M. L. Figueiredo, and A. P. Leite, 6th European Conference on Integrated Optics (ECIO 1993), Conference Proceedings, pp. 9-10. 
  
• POPCORN: A Novel Technology for Polymer Based Integrated Optics, H. Kragl representing the consortium partners in the project CEC-RACE II POPCORN, 6th European Conference on Integrated Optics (ECIO'93), Conference Proceedings, pp. 9-24.  
  

Patent applications:

• Methods and systems for optoelectronic oscillators, B. Romeira, J. M. L. Figueiredo, C. N. Ironside, T. J. Slight, Universidade do Algarve, Portugal, 2010, Patent Application 104973 (filing date 17-02-2010).
  
• Interfaces and Method For Wireless-Optical and Optical-Wireless Conversion, J. M. L. Figueiredo, B. Romeira, C. N. Ironside, T. J. Slight, University of Glasgow, UK, 2010, Patent Applications GB2465184-A (publication date 12-05-2010); WO2010052481-A1 (publication date 14-05-2010). 
  
• Optoelectronic Device, C. N. Ironside,  J. M. L. Figueiredo, University of Glasgow, UK, 2004, Patent Application US 20040247218 A1 (publication date 9-12-2004). 
  
• Improved Optoelectronic Device, C. N. Ironside, J. M. L. Figueiredo, University of Glasgow, UK, 2002, Patent Applications WO02088834 (publication date 7-11-2002); JP2004524589T (publication date 2004-08-12), EP1381909 (publication date 2004-01-21), WO02088834 A3 (publication date 2003-04-17), CA2445566 (publication date 2002-11-07), WO02088834 A2 (publication date 2002-11-07). This technology was licensed to Essient Photonics Ltd, a spin-out from Glasgow University, launched in 2002. 
  
• Improved Optoelectronic Device, C. N. Ironside, C. R. Stanley, J. M. L. Figueiredo, University of Glasgow, UK, 2000, Patent Applications WO0072383, (publication date 30-11-2000); CA2398287 (publication date 2002-07-24), EP1183736 (publication date 2000-11-30), AU5092500 (publication date 2000-11-30), WO0072383 (publication date 2000-11-30). This technology was licensed to Essient Photonics Ltd, a spin-out from Glasgow University, launched in 2002. 
  

 
Thesis and reports:

• Optoelectronic Properties of Resonant Tunneling Diodes, doctorate thesis in Physics, Universidade do Porto in co-tutela with the University of Glasgow, 2000.
• Dispositivos Ópticos Integrados para Multiplexagem de Comprimentos de Onda, Master thesis in Optoelectronics and Lasers, Universidade do Porto, 1995.
• Holographic optical elements aberration correction with an intermediate computer generated hologram, Physics (Electronics and Optics) degree final project report, realized under the Erasmus programme at the Vrije Universiteit Brussels and submitted to the Universidade do Porto, 1991. 
  

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Departamento de Física & CEOT-UALG, Faculdade de Ciências e Tecnologia, Universidade do Algarve, Campus de Gambelas, 8005-139 FARO, Portugal. E-mail: jlongras@ualg.pt, URL: http://w3.ualg.pt/~jlongras/